Well this is pretty interested: was first sounded like there was a ridiculous job in NASA defending us from Aliens, actually sounds like a pretty interesting position. Basically, NASA is hiring to make sure when exploring space, we avoid accidentally contaminating Earth with foreign bacteria or matter from Mars, and vice versa. Not that I think there is anything truly malicious or anything that would make for a science horror film, but invasive species of flora and insects are totally a thing here, so why not be concerned about the same thing across planets.